Question 3
(a) Complete the table below.
Symptom |
Deficient nutrient |
Fertilizer to supply the deficient nutrient |
Brown colour at the margin of leaves |
(i) |
(ii) |
Chlorosis along the leaf |
(iii) |
(iv) |
(v) |
Nitrogen |
(vi) |
(vii) |
Phosphorus |
(viii) |
(8 marks)
(b) Explain each of the following terms in forest management:
(i) reforestation;
(ii) afforestation;
(iii) selective exploitation. (6 marks)
(c) Name four ornamental trees that are used as shade. (4 marks)
Observation
Question 3 was not popular among candidates and few of them attempted it.
Most candidates could not complete the table on plant nutrients as well as explain
reforestation and afforestation. Only few candidates could name ornamental trees
that are used as shade.
The expected answers include:
(a) Completion of table on plant nutrients
Symptom |
Deficient nutrient |
Fertilizer to supply deficient nutrient |
Brown colour at the margin of leaves |
(i) Potassium |
(ii) - Wood ash |
Chlorosis along the leaf |
(iii) Magnesium |
(iv) - Dolomite |
(v) Yellowing of leaves |
- Nitrogen |
(vi) - Ammonium sulphate |
(vii) Purple brown colour |
- Phosphorus |
(viii) - Single superphosphate |
(b) Explanation of terms in forest management
(i) Reforestation
- Reforestation is the replanting/restoration of forests in areas where forest
trees have been removed or destroyed by human activities
- It is carried out by natural seeding or by artificial planting of seeds/
young tree seedlings
(ii) Afforestation
- Afforestation is the process pf establishing forests in areas that have
never been forested/areas where forests never existed
- It is carried out to reduce desert encroachment
- Forest tree species that can withstand drought and high temperature are
usually used
(iii) Selective exploitation
- Selective exploitation is the process of cutting/harvesting only mature
trees in a forest
- Trees are harvested based on the age, girth and species
- It ensures sustainable supply of timber
(c) Ornamental trees that are used as shade
- Almond - Eucalyptus - Frangipani
- Cassia - Flamboyante - Gliricidia
- Neem - Casuarina